1. Field of the Invention
This invention relates to a wireless communication equipment system and a wireless communication sequence for the same. More specifically, the present invention relates to a wireless communication equipment system capable of communicating through broadcast (BC) frames and multicast (MC) frames under a wireless local area network (LAN) environment, and a wireless communication sequence for the system.
2. Description of the Related Art
Recently, wireless LAN communication as wireless communication equipment systems has become widely used. Communication, which is implemented in accordance with a frame format and a communication control protocol specified in the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, can be regarded as the wireless LAN communication (e.g., refer to IEEE 802.11:ISO/IEC8802-11:1999(E) ANSI/IEEE Std. 802.11, 1999 Edition).
As regards a data communication system in a medium access controller (MAC) layer level based on the IEEE 802.11 standards of this wireless LAN communication, three kinds of systems are defined. The three kinds of systems include a unicast system performing a data transmission to a specified one terminal, a broadcast system performing data transmissions to all the terminals and a multicast system performing data transmissions to one or more specified terminals. Among of them, the unicast system adopts a scheme conducting transmission acknowledgement for the data transmission. However the scheme of the transmission acknowledgement for the data transmission is not adopted into the broadcast system and the multicast system. Therefore, in the case of the broadcast system and the multicast system, even if a frame loss occurs and a side of a partner's (reception) terminal cannot receive a frame, a side of a transmission terminal cannot recognize the fact, and cannot perform a re-transmission of the frame.
That is, a protocol sequence using control and a management frame stated in the IEEE 802.11e standards and standards compliant with these standards (refer to, e.g., IEEE 802.11e/D13.0, January 2005: ANSI/IEEE Std. 802.11-1999 [2003 Reaff] Edition) cannot perform an acknowledgement (ACK) transmission by means the broadcast frame and the multicast frame. In other words, the broadcast system and the multicast system stated in the IEEE 802.11 standards of the wireless LAN communication does not include a scheme in which the side of the transmission terminal recognizes whether or not the side of the partner's terminal has received the frame. Therefore, even when the frame loss occurs, the re-transmission of the lost frame may not be implemented.
In contrast, in the case of the unit cast frames since the scheme of the transmission acknowledgement has been established fundamentally, applying the scheme to the broadcast frame or the multicast frame is a possible approach. However, since the applying of the scheme to the broadcast frame or the multicast frame generates a collision of transmission confirmation frames in a wireless section, the wireless communication system encounters such a problem that it cannot normally transmit the acknowledgement frame to the side of the transmission terminal.